1. Technical Field
The present invention relates to a manual litter box and, more particularly, to a manual cleaning litter box having a handle connected to a shuttle carriage attached to a rake assembly movable across a disposable litter tray cartridge to clean animal waste therefrom.
2. Description of the Prior Art
Various litter boxes are known in the art. Both reusable and disposable litter boxes are known. Reusable litter boxes are normally formed from plastic and are configured as a rectangular tray with 3-4 inch sidewalls. Normally, such reusable litter boxes need to be maintained daily or every few days. In order to facilitate the care and cleaning of litter boxes, disposable litter boxes have been developed. Examples of such disposable litter boxes are disclosed in U.S. Pat. Nos. 4,171,680; 4,271,787, 6,065,429. Such disposable litter boxes normally include a disposable box or tray filled with an absorbent material, commonly known as kitty litter.
In order to further facilitate the upkeep of such litter boxes, both self-cleaning and manual litter boxes have been developed. One such self-cleaning litter box that has solved the problem of removing animal waste efficiently is found in pending patent application Ser. No. 10/574,068 (“068”) entitled “Self-cleaning Litter Box”. However, other commercially available self-cleaning and manual litter boxes primarily use “clay” or “clumping” litters and require the periodic addition of fresh kitty litter and the removal of waste every few days. Examples of such manual litter boxes are disclosed in U.S. Pat. Nos. 2,971,493; 3,752,120; 3,908,597; 4,359,966; 4,870,924; 5,372,095 and 7,395,784, hereby incorporated by reference.
U.S. Pat. No. 4,870,924 ('924) discloses a manual litter box which includes the type of manual removal of the animal waste where the removal of the litter brings the end user in potential contact with the animal waste when cleaning out the litter box. '924 patent includes generally a rectangular litter receptacle or tray 12, a tray cover 14, disposable feces filters 16 and a filter protector 18 in which a quantity of litter material 20. Each disposable feces filter 16 includes straps 66 at the corners to lift out of the tray 12 wherein the litter material passes through holes in the filter but captures the animal feces. Then the filter can be placed in a plastic bag or the like for final disposal. In short, all of the above mentioned patents involve similar removal of various filters, shifters or trays with various holes therein to dispose of the animal waste in which the pet owner may come into contact with the animal waste during cleaning of the litter box or at the final disposal of the filters, shifters or trays.
Self-cleaning litter boxes like the one found in pending '068 patent application is an automatic self-cleaning litter box with a motorized rake assembly and a disposable cartridge tray that shows one way to avoid coming in contact with the animal waste. This automatic litter box described in this patent application is a consistently clean, free of hassles involving animal waste and other problems experienced by other known prior art self-cleaning litter boxes and its automation feature allows it to be left alone for weeks at a time. With its disposable litter tray cartridge where the waste is combed into a waste compartment at one end of the disposable tray, this automatic self-cleaning litter box is also convenient when a power source is available.
U.S. Pat. Nos. 5,477,812; 6,082,302; 6,378,461; and Re. 36,847 also disclose self-cleaning litter boxes. These self-cleaning litter boxes disclosed in these patents including many different configurations and use various litters within their litter trays.
But, there are various problems associated with either the self-cleaning or manual litter boxes disclosed in the above-mentioned U.S. patents. First, because these litter boxes often require the use of clumping litter, the waste bin fills quickly with clumped urine and solid waste. Therefore the waste bin must be emptied every few days or more frequently, especially in multiple cat applications. Second, removal of the waste container is cumbersome and often requires the user to come in contact with the waste. Third, fresh kitty litter must be added to the litter tray on an on-going basis. Fourth, the drive assembly of some self-cleaning litter boxes is known to include a drive motor that travels with the rake assembly in a toothed track that is exposed to the litter area. By mounting the motor to the rake, electrical power is applied to a movable chassis, thus requiring a take up reel for an electrical cord, which is known to be inherently risky and prone to failure. When too much litter is used in the litter tray, the motor can be insufficient to drive the rake through the litter, thereby causing a jam which requires the owner to intervene. Conversely, if too little litter is used, or if the cat redistributes the litter in a particular way, a clump can cement to the bottom of the litter pan and prevent the rake from passing through the litter area. In other instances, the cat causes litter to accumulate in the tracks, also causing damage to the drive system and/or requiring further user intervention. Further, the electrical motor is not fully protected from urine, and can be damaged by the cat through normal operation. Also, motors are known to be loud if the litter box is placed in close proximity to the user. Fifth, once again some self-cleaning litter boxes before the '068 patent application are not suitable for use with crystal litter. In particular, due to the irregular shape of the crystal litter and tendency to pack and interlock, a wave tends to build up in front of the rake assembly, which among other things, may prevent the rake assembly from completing a cleaning stroke.
Thus it is desirable to have a manual litter box too, which may include some of the same good design features of the automatic self-cleaning litter box of the pending '068 patent application. This invention is capable of providing similar desirable features only without a motor when power is unavailable or not desirable to use in a particular application. The performance of the present invention of clearing animal waste out of the litter within the litter box is easier than some of the above cited manual litter boxes; is more reliable; does not expose mechanical components to contamination; and is suitable for use with non-clumping litters such as crystal litter.
Therefore, when a power source is unavailable such as a time when a litter box is taken on a family vacation, it is desirable to use a manual litter box that avoids the above mentioned problems with filters, shifters and trays as well as the clumping of the litter material encountered by both the known self-cleaning and manual litter boxes where the entire system must be periodically emptied and disassembled for cleaning. Also, the relative complexity of these above described prior art litter boxes result in the cost of each litter box being relatively expensive.
Thus, the desirable litter box is a manual cleaning litter box with a number of the same features in handling the animal waste with a disposable litter tray as found in pending '068 patent application (hereby incorporated by reference thereto).